Sofa



FIG. 1 is a front view of a sofa;

FIG. 2 is a left side perspective view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a top view thereof; and,

FIG. 6 is bottom view thereof. 

CLAIM The ornamental design for a sofa, as shown and described. 